mazer 0.0.13

Library for generating and solving mazes of various maze algorithms and grid types
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204

use crate::behaviors::maze::MazeGeneration;
use crate::algorithms::MazeAlgorithm;
use crate::grid::Grid;
use crate::cell::{Coordinates, MazeType};
use crate::error::Error;

use std::collections::HashSet;

use serde::{Serialize, Deserialize};

#[derive(Debug, Copy, Clone, PartialEq, Serialize, Deserialize)]
pub enum SelectionStrategy {
    Random,
    Newest,
}

pub struct GrowingTree {
    pub strategy: SelectionStrategy,
}

impl MazeGeneration for GrowingTree {
    fn generate(&self, grid: &mut Grid) -> Result<(), Error> {
        if grid.maze_type == MazeType::Rhombic {
            match self.strategy {
                SelectionStrategy::Newest | SelectionStrategy::Random => {
                    return Err(Error::AlgorithmUnavailableForMazeType {
                        algorithm: match self.strategy {
                            SelectionStrategy::Newest => MazeAlgorithm::GrowingTreeNewest,
                            SelectionStrategy::Random => MazeAlgorithm::GrowingTreeRandom,
                        },
                        maze_type: MazeType::Rhombic,
                    });
                }
            }
        }
        let mut active: Vec<Coordinates> = Vec::new();
        let mut visited: HashSet<Coordinates> = HashSet::new();

        // Start with a random cell
        let start_coords = Coordinates {
            x: grid.bounded_random_usize(grid.width),
            y: grid.bounded_random_usize(grid.height),
        };
        active.push(start_coords);
        visited.insert(start_coords);

        // Capture initial state with no changed cells
        if grid.capture_steps {
            let changed_cells = HashSet::new();
            self.capture_step(grid, &changed_cells);
        }

        while !active.is_empty() {
            // Choose a cell from active list based on strategy
            let index = match self.strategy {
                SelectionStrategy::Random => grid.bounded_random_usize(active.len()),
                SelectionStrategy::Newest => active.len() - 1,
            };
            let current_coords = active[index];

            // Get unvisited neighbors
            let unvisited_neighbors: Vec<Coordinates> = if let Ok(cell) = grid.get(current_coords) {
                cell.neighbors()
                    .into_iter()
                    .filter(|neighbor| !visited.contains(neighbor))
                    .collect()
            } else {
                Vec::new()
            };

            if unvisited_neighbors.is_empty() {
                // No unvisited neighbors, remove from active list
                active.swap_remove(index);
            } else {
                // Choose a random unvisited neighbor
                let neighbor_index = grid.bounded_random_usize(unvisited_neighbors.len());
                let next_coords = unvisited_neighbors[neighbor_index];

                // Link to the neighbor
                grid.link(current_coords, next_coords)?;

                // Mark neighbor as visited and add to active list
                visited.insert(next_coords);
                active.push(next_coords);

                // Capture step with changed cells after linking
                if grid.capture_steps {
                    let mut changed_cells = HashSet::new();
                    changed_cells.insert(current_coords);
                    changed_cells.insert(next_coords);
                    self.capture_step(grid, &changed_cells);
                }
            }
        }

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::cell::{MazeType, Coordinates};

    #[test]
    fn generate_and_print_5_x_5_orthogonal_maze() {
        match Grid::new(MazeType::Orthogonal, 4, 4, Coordinates { x: 0, y: 0 }, Coordinates { x: 3, y: 3 }, false) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Random }.generate(&mut grid).expect("Growing Tree maze generation failed");
                println!("\n\nGrowing Tree\n\n{}\n\n", grid.to_asci());
                assert!(grid.is_perfect_maze().unwrap());
            }
            Err(e) => panic!("Unexpected error running test: {:?}", e),
        }
    }

    #[test]
    fn generate_and_print_12_x_6_orthogonal_maze() {
        match Grid::new(MazeType::Orthogonal, 12, 6, Coordinates { x: 0, y: 0 }, Coordinates { x: 11, y: 5 }, false) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Newest }.generate(&mut grid).expect("Growing Tree maze generation failed");
                println!("\n\nGrowing Tree\n\n{}\n\n", grid.to_asci());
                assert!(grid.is_perfect_maze().unwrap());
            }
            Err(e) => panic!("Unexpected error running test: {:?}", e),
        }
    }

    #[test]
    fn generate_5_x_5_delta_maze() {
        match Grid::new(MazeType::Delta, 4, 4, Coordinates { x: 0, y: 0 }, Coordinates { x: 3, y: 3 }, false) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Random }.generate(&mut grid).expect("Growing Tree maze generation failed");
                assert!(grid.is_perfect_maze().unwrap());
            }
            Err(e) => panic!("Unexpected error running test: {:?}", e),
        }
    }

    #[test]
    fn generate_12_x_6_delta_maze() {
        match Grid::new(MazeType::Delta, 12, 6, Coordinates { x: 0, y: 0 }, Coordinates { x: 11, y: 5 }, false) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Newest }.generate(&mut grid).expect("Growing Tree maze generation failed");
                assert!(grid.is_perfect_maze().unwrap());
            }
            Err(e) => panic!("Unexpected error running test: {:?}", e),
        }
    }

    #[test]
    fn generate_5_x_5_sigma_maze() {
        match Grid::new(MazeType::Sigma, 4, 4, Coordinates { x: 0, y: 0 }, Coordinates { x: 3, y: 3 }, false) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Random }.generate(&mut grid).expect("Growing Tree maze generation failed");
                assert!(grid.is_perfect_maze().unwrap());
            }
            Err(e) => panic!("Unexpected error running test: {:?}", e),
        }
    }

    #[test]
    fn generate_12_x_6_sigma_maze() {
        match Grid::new(MazeType::Sigma, 12, 6, Coordinates { x: 0, y: 0 }, Coordinates { x: 11, y: 5 }, false) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Newest }.generate(&mut grid).expect("Growing Tree maze generation failed");
                assert!(grid.is_perfect_maze().unwrap());
            }
            Err(e) => panic!("Unexpected error running test: {:?}", e),
        }
    }

    #[test]
    fn test_growing_tree_with_capture_steps() {
        let start = Coordinates { x: 0, y: 0 };
        let goal = Coordinates { x: 11, y: 11 };
        match Grid::new(MazeType::Orthogonal, 12, 12, start, goal, true) {
            Ok(mut grid) => {
                assert!(!grid.is_perfect_maze().unwrap());
                GrowingTree{ strategy: SelectionStrategy::Random }.generate(&mut grid).expect("Maze generation failed");
                assert!(grid.is_perfect_maze().unwrap());
                assert!(grid.generation_steps.is_some());
                let steps = grid.generation_steps.as_ref().unwrap();
                assert!(!steps.is_empty());
                // Check if any cells become linked across all generation steps
                let has_linked_cells = steps.iter().any(|step| {
                    step.cells.iter().filter_map(|opt| opt.as_ref()).any(|cell| !cell.linked.is_empty())
                });
                assert!(has_linked_cells, "No cells were linked during maze generation");
                let has_open_walls = steps.iter().any(|step| {
                    step.cells.iter().filter_map(|opt| opt.as_ref()).any(|cell| !cell.open_walls.is_empty())
                });
                assert!(has_open_walls, "No cells have open walls in generation steps");
            }
            Err(e) => panic!("Unexpected error generating grid: {:?}", e),
        }
    }
}